Oil Exporters to the Euro's Rescue?

Energy-exporting countries have more at risk than any other participant in the world economy if the euro crisis plunges Europe into recession. These countries would likely experience greater losses in 2012 should Europe fail. Oil and natural gas prices would plummet, and the price collapse would likely be larger than the 2008–09 decline. Energy-exporting countries therefore should be working feverishly with the International Monetary Fund (IMF) and the European Union to rescue the euro. They, along with China and other large holders of foreign exchange reserves, should lend to the IMF to help it construct an emergency lending facility with capacity of more than €1 trillion. The fund, administered by the IMF, would be used to buy bonds issued by Greece, Italy, Spain, Portugal, and Ireland. The goal should be to bring interest rates on long-term bonds down to 3 percent. Simultaneously, efforts should be redoubled to fix the economic problems in the troubled nations and restore balance to their budgets. An energy price collapse would increase disruptions in energy-exporting countries, promote economic ills in some consuming nations, such as Canada, and almost certainly start yet a third, even more violent, economic cycle.

String Webs from Field Theory

The spectrum of stable electrically and magnetically charged supersymmetric particles can change discontinuously as one changes the vacuum on the Coulomb branch of gauge theories with extended supersymmetry in four dimensions. We show that this decay process can be understood and is well described by semiclassical field configurations purely in terms of the low energy effective action on the Coulomb branch even when it occurs at strong coupling. The resulting picture of the stable supersymmetric spectrum is a generalization of the ``string web'' picture of these states found in string constructions for certain theories.Comment: 53 pages, 6 figures; more references adde

Using US Strategic Reserves to Moderate Potential Oil Price Increases from Sanctions on Iran

The new, draconian sanctions introduced by the United States and the European Union to prevent Iran from earning money from its crude oil exports could pose a serious economic threat to oil-importing countries that also trade heavily with the US and EU economies. Nations such as China, South Korea, and Japan, which obtain significant amount of oil from Iran while enjoying large trade surpluses with the United States, are justifiably anxious. These countries and others worry that by pushing Iran from the global crude market, the new US and EU sanctions will disrupt oil markets, increase crude prices, and further slow global economic growth, which, at a minimum, would cut their export revenues. Saudi Arabia and other members of the Oil and Petroleum Exporting Countries (OPEC) have indicated they would replace oil previously purchased from Iran, but these offers have done little to allay the apprehensions. Verleger suggests a way to put real pressure on Iran while moderating or eliminating economic fallout for the US and EU economies and those of their trading partners: selling oil from the US Strategic Petroleum Reserve (SPR), which now holds far more oil than required by treaty obligations—more than 280 million surplus barrels. This strategic use of the SPR will increase the effectiveness of sanctions on Iran and ease the adjustment difficulties that confront US allies. The sales might also reduce any price pressure caused by removal of light Iranian crude from the market.

First passage time density for the Ehrenfest model

We derive an explicit expression for the probability density of the first passage time to state 0 for the Ehrenfest diffusion model in continuous time

Classifying general nonlinear force laws in cell-based models via the continuum limit

though discrete cell-based frameworks are now commonly used to simulate a whole range of biological phenomena, it is typically not obvious how the numerous different types of model are related to one another, nor which one is most appropriate in a given context. Here we demonstrate how individual cell movement on the discrete scale modeled using nonlinear force laws can be described by nonlinear diffusion coefficients on the continuum scale. A general relationship between nonlinear force laws and their respective diffusion coefficients is derived in one spatial dimension and, subsequently, a range of particular examples is considered. For each case excellent agreement is observed between numerical solutions of the discrete and corresponding continuum models. Three case studies are considered in which we demonstrate how the derived nonlinear diffusion coefficients can be used to (a) relate different discrete models of cell behavior; (b) derive discrete, intercell force laws from previously posed diffusion coefficients, and (c) describe aggregative behavior in discrete simulations